rust-status: add util for listing a directory

I debated moving it to utils, but it is not used anywhere else for now, and
its skip behavior is pretty specific to status.

Differential Revision: https://phab.mercurial-scm.org/D7927

rust/hg-core/src/dirstate/status.rs

@@ -1,306 +1,335 b''
 // status.rs
 //
 // Copyright 2019 Raphaël Gomès <[e-mail]>
 //
 // This software may be used and distributed according to the terms of the
 // GNU General Public License version 2 or any later version.
 
 //! Rust implementation of dirstate.status (dirstate.py).
 //! It is currently missing a lot of functionality compared to the Python one
 //! and will only be triggered in narrow cases.
 
 use crate::{
     dirstate::SIZE_FROM_OTHER_PARENT,
     matchers::Matcher,
     utils::{
         files::HgMetadata,
-        hg_path::{hg_path_to_path_buf, HgPath},
+        hg_path::{
+            hg_path_to_path_buf, os_string_to_hg_path_buf, HgPath, HgPathBuf,
+        },
     },
     CopyMap, DirstateEntry, DirstateMap, EntryState,
 };
 use rayon::prelude::*;
 use std::collections::HashSet;
+use std::fs::{read_dir, DirEntry};
 use std::path::Path;
 
 /// Marker enum used to dispatch new status entries into the right collections.
 /// Is similar to `crate::EntryState`, but represents the transient state of
 /// entries during the lifetime of a command.
 enum Dispatch {
     Unsure,
     Modified,
     Added,
     Removed,
     Deleted,
     Clean,
     Unknown,
 }
 
 type IoResult<T> = std::io::Result<T>;
 
 /// Dates and times that are outside the 31-bit signed range are compared
 /// modulo 2^31. This should prevent hg from behaving badly with very large
 /// files or corrupt dates while still having a high probability of detecting
 /// changes. (issue2608)
 /// TODO I haven't found a way of having `b` be `Into<i32>`, since `From<u64>`
 /// is not defined for `i32`, and there is no `As` trait. This forces the
 /// caller to cast `b` as `i32`.
 fn mod_compare(a: i32, b: i32) -> bool {
     a & i32::max_value() != b & i32::max_value()
 }
 
+/// Return a sorted list containing information about the entries
+/// in the directory.
+///
+/// * `skip_dot_hg` - Return an empty vec if `path` contains a `.hg` directory
+fn list_directory(
+    path: impl AsRef<Path>,
+    skip_dot_hg: bool,
+) -> std::io::Result<Vec<(HgPathBuf, DirEntry)>> {
+    let mut results = vec![];
+    let entries = read_dir(path.as_ref())?;
+
+    for entry in entries {
+        let entry = entry?;
+        let filename = os_string_to_hg_path_buf(entry.file_name())?;
+        let file_type = entry.file_type()?;
+        if skip_dot_hg && filename.as_bytes() == b".hg" && file_type.is_dir() {
+            return Ok(vec![]);
+        } else {
+            results.push((HgPathBuf::from(filename), entry))
+        }
+    }
+
+    results.sort_unstable_by_key(|e| e.0.clone());
+    Ok(results)
+}
+
 /// The file corresponding to the dirstate entry was found on the filesystem.
 fn dispatch_found(
     filename: impl AsRef<HgPath>,
     entry: DirstateEntry,
     metadata: HgMetadata,
     copy_map: &CopyMap,
     check_exec: bool,
     list_clean: bool,
     last_normal_time: i64,
 ) -> Dispatch {
     let DirstateEntry {
         state,
         mode,
         mtime,
         size,
     } = entry;
 
     let HgMetadata {
         st_mode,
         st_size,
         st_mtime,
         ..
     } = metadata;
 
     match state {
         EntryState::Normal => {
             let size_changed = mod_compare(size, st_size as i32);
             let mode_changed =
                 (mode ^ st_mode as i32) & 0o100 != 0o000 && check_exec;
             let metadata_changed = size >= 0 && (size_changed || mode_changed);
             let other_parent = size == SIZE_FROM_OTHER_PARENT;
             if metadata_changed
                 || other_parent
                 || copy_map.contains_key(filename.as_ref())
             {
                 Dispatch::Modified
             } else if mod_compare(mtime, st_mtime as i32) {
                 Dispatch::Unsure
             } else if st_mtime == last_normal_time {
                 // the file may have just been marked as normal and
                 // it may have changed in the same second without
                 // changing its size. This can happen if we quickly
                 // do multiple commits. Force lookup, so we don't
                 // miss such a racy file change.
                 Dispatch::Unsure
             } else if list_clean {
                 Dispatch::Clean
             } else {
                 Dispatch::Unknown
             }
         }
         EntryState::Merged => Dispatch::Modified,
         EntryState::Added => Dispatch::Added,
         EntryState::Removed => Dispatch::Removed,
         EntryState::Unknown => Dispatch::Unknown,
     }
 }
 
 /// The file corresponding to this Dirstate entry is missing.
 fn dispatch_missing(state: EntryState) -> Dispatch {
     match state {
         // File was removed from the filesystem during commands
         EntryState::Normal | EntryState::Merged | EntryState::Added => {
             Dispatch::Deleted
         }
         // File was removed, everything is normal
         EntryState::Removed => Dispatch::Removed,
         // File is unknown to Mercurial, everything is normal
         EntryState::Unknown => Dispatch::Unknown,
     }
 }
 
 /// Get stat data about the files explicitly specified by match.
 /// TODO subrepos
 fn walk_explicit<'a>(
     files: &'a HashSet<&HgPath>,
     dmap: &'a DirstateMap,
     root_dir: impl AsRef<Path> + Sync + Send,
     check_exec: bool,
     list_clean: bool,
     last_normal_time: i64,
 ) -> impl ParallelIterator<Item = IoResult<(&'a HgPath, Dispatch)>> {
     files.par_iter().filter_map(move |filename| {
         // TODO normalization
         let normalized = filename.as_ref();
 
         let buf = match hg_path_to_path_buf(normalized) {
             Ok(x) => x,
             Err(e) => return Some(Err(e.into())),
         };
         let target = root_dir.as_ref().join(buf);
         let st = target.symlink_metadata();
         match st {
             Ok(meta) => {
                 let file_type = meta.file_type();
                 if file_type.is_file() || file_type.is_symlink() {
                     if let Some(entry) = dmap.get(normalized) {
                         return Some(Ok((
                             normalized,
                             dispatch_found(
                                 &normalized,
                                 *entry,
                                 HgMetadata::from_metadata(meta),
                                 &dmap.copy_map,
                                 check_exec,
                                 list_clean,
                                 last_normal_time,
                             ),
                         )));
                     }
                 } else {
                     if dmap.contains_key(normalized) {
                         return Some(Ok((normalized, Dispatch::Removed)));
                     }
                 }
             }
             Err(_) => {
                 if let Some(entry) = dmap.get(normalized) {
                     return Some(Ok((
                         normalized,
                         dispatch_missing(entry.state),
                     )));
                 }
             }
         };
         None
     })
 }
 
 /// Stat all entries in the `DirstateMap` and mark them for dispatch into
 /// the relevant collections.
 fn stat_dmap_entries(
     dmap: &DirstateMap,
     root_dir: impl AsRef<Path> + Sync + Send,
     check_exec: bool,
     list_clean: bool,
     last_normal_time: i64,
 ) -> impl ParallelIterator<Item = IoResult<(&HgPath, Dispatch)>> {
     dmap.par_iter().map(move |(filename, entry)| {
         let filename: &HgPath = filename;
         let filename_as_path = hg_path_to_path_buf(filename)?;
         let meta = root_dir.as_ref().join(filename_as_path).symlink_metadata();
 
         match meta {
             Ok(ref m)
                 if !(m.file_type().is_file()
                     || m.file_type().is_symlink()) =>
             {
                 Ok((filename, dispatch_missing(entry.state)))
             }
             Ok(m) => Ok((
                 filename,
                 dispatch_found(
                     filename,
                     *entry,
                     HgMetadata::from_metadata(m),
                     &dmap.copy_map,
                     check_exec,
                     list_clean,
                     last_normal_time,
                 ),
             )),
             Err(ref e)
                 if e.kind() == std::io::ErrorKind::NotFound
                     || e.raw_os_error() == Some(20) =>
             {
                 // Rust does not yet have an `ErrorKind` for
                 // `NotADirectory` (errno 20)
                 // It happens if the dirstate contains `foo/bar` and
                 // foo is not a directory
                 Ok((filename, dispatch_missing(entry.state)))
             }
             Err(e) => Err(e),
         }
     })
 }
 
 pub struct StatusResult<'a> {
     pub modified: Vec<&'a HgPath>,
     pub added: Vec<&'a HgPath>,
     pub removed: Vec<&'a HgPath>,
     pub deleted: Vec<&'a HgPath>,
     pub clean: Vec<&'a HgPath>,
     /* TODO ignored
      * TODO unknown */
 }
 
 fn build_response<'a>(
     results: impl IntoIterator<Item = IoResult<(&'a HgPath, Dispatch)>>,
 ) -> IoResult<(Vec<&'a HgPath>, StatusResult<'a>)> {
     let mut lookup = vec![];
     let mut modified = vec![];
     let mut added = vec![];
     let mut removed = vec![];
     let mut deleted = vec![];
     let mut clean = vec![];
 
     for res in results.into_iter() {
         let (filename, dispatch) = res?;
         match dispatch {
             Dispatch::Unknown => {}
             Dispatch::Unsure => lookup.push(filename),
             Dispatch::Modified => modified.push(filename),
             Dispatch::Added => added.push(filename),
             Dispatch::Removed => removed.push(filename),
             Dispatch::Deleted => deleted.push(filename),
             Dispatch::Clean => clean.push(filename),
         }
     }
 
     Ok((
         lookup,
         StatusResult {
             modified,
             added,
             removed,
             deleted,
             clean,
         },
     ))
 }
 
 pub fn status<'a: 'c, 'b: 'c, 'c>(
     dmap: &'a DirstateMap,
     matcher: &'b impl Matcher,
     root_dir: impl AsRef<Path> + Sync + Send + Copy,
     list_clean: bool,
     last_normal_time: i64,
     check_exec: bool,
 ) -> IoResult<(Vec<&'c HgPath>, StatusResult<'c>)> {
     let files = matcher.file_set();
     let mut results = vec![];
     if let Some(files) = files {
         results.par_extend(walk_explicit(
             &files,
             &dmap,
             root_dir,
             check_exec,
             list_clean,
             last_normal_time,
         ));
     }
 
     if !matcher.is_exact() {
         let stat_results = stat_dmap_entries(
             &dmap,
             root_dir,
             check_exec,
             list_clean,
             last_normal_time,
         );
         results.par_extend(stat_results);
     }
 
     build_response(results)
 }